The present invention relates to novel, fluorosilicone fluids, and more particularly, to fluorosilicone fluids useful as high-density fluid ocular tamponades, methods of producing the fluorosilicone fluids and methods of using the fluorosilicone fluids in vitreoretinal surgical procedures.
Ocular tamponades are vitreous substitutes that are used to reposition the retina of an eye in instances where a reattachment is not achievable by natural healing or by laser coagulation. The purpose of a vitreous substitute is to provide long-term tamponade of the retina, i.e., exhibit an ideal tamponade pressure (force/area) to position and maintain the retina in place while not damaging the retina. The tamponade pressure is a function of the density of the tamponade polymer and the volume occupied thereby in the vitreous. The ideal tamponade is non-toxic, chemically inert and highly transparent. Current commercially used tamponades include perfluorocarbon-liquids, balanced salt solutions, silicone oil or fluid and gases, such as air, sulfur hexafluoride (SF6) and perfluorocarbons (PFCs). The type of tamponade used depends on the severity of the retinal detachment. The addition of a PFC fluid that has a high specific gravity of approximately 1.7 to 2.0 g/cm3 expulses the subretinal fluid into the vitreous cavity and pushes the retina into place. Such fluids reposition the detached retina very effectively, but can only be used for short-term application because with long term PFC fluid use, retinal necrosis occurs. This is believed to be due to a combination of the high solubility of oxygen in the PFC fluids and the high density of the PFC fluids. Silicone oil is the preferred tamponade in cases of severe detachment, where the tamponade will be used six months or longer. Silicone oil, however, has a density of less than 1 (0.98 g/cm3) and is therefore only useful for retinal detachment of the superior portion of the eye. The silicone oil in the vitreous will migrate to the upper position of the vitreous only and is unacceptable in cases of lower retinal detachments or where there may be a risk of vitreoretinopathy in the lower position of the vitreous. Further, for the aphakic eye, the silicone oil will tend to move to the anterior chamber of the eye during sleep and come in contact with the corneal endothelium, creating a number of serious ocular defects.
Because of the noted shortcomings of current, commercially available ocular tamponades, there is a need for ocular tamponades that are relatively easy to synthesize and purify and that both the viscosity and density can be controlled.
The present invention is a novel high-density vitreoretinal fluid tamponade that is based on a fluorosilicone fluid. Preferred fluorosilicone fluids of the present invention have the general structure illustrated in Formula 1 below: 
wherein x is an integer less than 500; y is an integer less than 500; x+y is equal to an integer greater than 1 and less than 1000; z is an integer less than 100; and R is selected from the group consisting of hydrogen and fluorine.
The high-density fluorosilicone fluid vitreoretinal tamponades of the present invention are relatively easy to synthesize and purify. Likewise, both the viscosity and density can be controlled through the respective degree of polymerization and degree of fluoro side-chain substitution.
Accordingly, it is an object of the present invention to provide a high-density vitreoretinal tamponade.
Another object of the present invention is to provide a process for the manufacture of a high-density vitreoretinal tamponade.
Another object of the present invention is to provide a process for using a high-density vitreoretinal tamponade in a surgical procedure.
Another object of the present invention is to provide a process for manufacturing vitreoretinal tamponades that allows for control of the density and viscosity of the vitreoretinal tamponade .
Still another object of the present invention is to provide a vitreoretinal tamponade suitable for relatively long term use in an eye.
A further object of the present invention is to provide a process for manufacturing and using a vitreoretinal tamponade suitable for relatively long term use in an eye.
These and other objectives and advantages of the present invention, some of which are specifically described and others that are not, will become apparent from the detailed description and claims that follow.